This invention generally relates to methods and apparatus for extruding food products, and more specifically to methods and apparatus for forming a food product with an open texture throughout the interior of the product but also having a smooth exterior surface.
Small bread- or crouton-like bits of food may be made by extruding a suitable food material, such as a cereal meal, into a long rope, tempering the rope to form an open texture inside the rope, and then cutting the rope into slices or pieces. These food bits resemble tiny slices of bread in that they, first, have an open texture throughout the interiors of the food bits and on the front and back faces that are formed when the individual slices are cut from the rope, and second, have a smooth skin or surface extending around the outside of the product, between those front and back faces.
The standard dies used in the above-described procedure determine the product shape, but these dies normally do not allow for the formation of the desired open texture in the interior of the extruded product, and instead a separate tempering and cutting step is needed to provide that texture.
In accordance with the present invention, it has been learned that by immediately expanding an extruded food material to, or at least substantially to, its final width as soon as that food material enters an expansion chamber of an extruded die, an open texture can be formed throughout the interior of the expanded food material, while at the same time, the food material can consistently be expanded into a product that will maintain its own shape after the product is discharged and sliced from the extruder die.